No reason for me to jump into this, and certainly not to be contrary, but ...
I wasn't absolutely certain, but having worked in banking for decades, I thought I recalled that the cited ban on surcharges expired some time ago. I did a little research and found this on the FDIC's current website
when I searched for "truth in lending credit card surcharge":
§ 167. Use of cash discounts
(a) With respect to credit card which may be used for extensions of credit in sales transactions in which the seller is a person other than the card issuer, the card issuer may not, by contract or otherwise, prohibit any such seller from offering a discount to a cardholder to induce the cardholder to pay by cash, check, or similar means rather than use a credit card.
(b) With respect to any sales transaction, any discount from the regular price offered by the seller for the purpose of inducing payment by cash, checks, or other means not involving the use of an open-end credit plan or a credit card shall not constitute a finance charge as determined under section 106, if such discount is offered to all prospective buyers and its availability is disclosed clearly and conspicuously.
[Codified to 15 U.S.C. 1666f]
[Source: Section 167 of title I of the Act of May 29, 1968 (Pub. L. No. 90-321), as added by section 306 of title III of the Act of October 28, 1974 (Pub. L. No. 93-495; 88 Stat. 1515), effective October 28, 1975, and as amended by section 3(c)(1) of the Act of February 27, 1976 (Pub. L. No. 94-222, 90 Stat. 197), effective February 27, 1976; and section 101 of title I of the Act of July 27, 1981 (Pub. L. No. 97-25; 95 Stat. 144), effective July 27, 1981]NOTE
Expiration date of § 167(a)(2). Section 3(c)(2) of the Act of February 27, 1976 (Pub. L. No. 94-222; 90 Stat. 197) as amended by section 201 of title II of the Act of July 27, 1981 (Pub. L. No. 97-25; 95 Stat. 144), states that section 167(a)(2) shall cease to be effective February 27, 1984.
Bold added by me. I also found on Google that some states have imposed a similar ban on credit card surcharges, but I can't cite any past or current regulatory verbiage on that.